How to measure a room for flooring, tile and paint

Accurate measurements save money and avoid a second trip to the store. A tape measure, a notepad and a simple sketch are all you need.

Floors: area

1. Sketch the room, including closets and alcoves.
2. Measure the length and width at the widest points, wall to wall, to the nearest inch.
3. Convert inches to feet by dividing by 12: 10 ft 6 in is 10.5 ft.
4. Multiply length × width for each rectangle.

L-shaped and irregular rooms

Split the room into rectangles. An L-shaped room made of a 12 × 10 ft area and a 6 × 4 ft nook is 120 + 24 = 144 sq ft. For angled walls, measure the triangle separately: base × height ÷ 2.

Walls: paintable area

Add the wall lengths and multiply by the height, then subtract doors and windows. See how much paint for a room.

Add a waste allowance

Metric conversions

1 metre = 3.281 feet. 1 square metre = 10.764 square feet. A 4 × 3.5 m room is 14 m², or about 151 sq ft.

Calculators

• Square footage
• Flooring
• Tile
• Concrete

Reviewed October 2026 · How we build our calculators · Report an issue